the general r a d i 0 · the general r a d i 0 volume 36 nos. 1 & 2 january.february, 1962...

THE GENERAL R A D I 0

VOLUME 36 Nos. 1 & 2 JANUARY.FEBRUARY, 1962

IET LABS, Inc in the GenRad tradition534 Main Street, Westbury, NY 11590

www.ietlabs.comTEL: (516) 334-5959 • (800) 899-8438 • FAX: (516) 334-5988

COVER

cas L .. b .. r .. t .. rI •• • .. ,w St ..... ph .... lc '.st .ec .. rd. 5' •• 100, II d .. I, .. o .. f ... .... with th. G. '"p. 1511_A Grephlc L.w,' •• _

cord ... S .. po,. 15.

THE GEN ERAL R A 0 I 0

fXPfR MfNTfR (\" 1"1-GINUAl 1.10010 COMPANY . WIST CONCOIO, MASS., U.S."'.

Publilhed Monthly by the General Radio Company

VOLUME 36· NUMBERS 1&2 JANU ARY.FEBRUARY, 1962

CONTENTS POI/.

A Test Oscillator for S-Band Measurements 3

More and Belter Pulses from the Unit Pulse Generator 8

Automatic Measurement of Phonograph Reproducers 15

More Talents, New Dress, for the Output Power Meter 21

The Measurement of the Ballistics of Indicating Instruments 23

Quantity Discounts for Coa)!'ial Connectors and Adaptors 24

G ENERA L RADIO COMPANY Well Concord, Massachusetts

ro/opholM !Con«>rdl 6 '7 fM""on 9· •• 00, 1&0.""'16" Mh .. on 6·7.00

NEW "O.IC,'

SY.ACUSE,

CHICAGO'

ar .... d AYlnu ... , U .. d . .. . . Id,ollo ld. N. w J.t •• y ro/.ph_ - N. Y •• :1 12 WOrth • • 2722

N. J .• 212 WHjtIM1 3 ·3 '",,0

Pl ..... d lulldl .. , . Eo.1 Men .. " ..... d . S".o.u.o II . N. Y.

relo-pltolM - 3 15 Gl ... ..- 4-9323

660S w ... N .. rth AY ....... Oo~ , ... ~. tIIl .... I. r~ - 3 12 Vlllafl" " ·9400

'HllAOEL'HIA : 1150 Y ..... ood. Ablnl . ..... ' ... ns"I" .. "I .. r~ _ Philo., "115 HArte .. ", 4·7419

Ab.ngton. 215 ru ...... 7 .".86

WASHINGTON, 1055 IJlh SI., Silwo. 5 .... 1 .. 1. Mo.ylo .. d r.loph_ -"102 JU,,_ 5· lOa!

flO.IOA , 113 EoII Colo"iol O.ly,. Orl .... d ... Florldo roleph_ - CArde" 5·.671

LOS ANGElES,' 1000 North Sowo.d St .. l ... A .. ,ol .. ll, CoUf. , .. ph_ - 2 fl HOllywood 9--620'

SAN FI.ANCISc(~.: 1116 Le. Aile. A wo .. l ... Allo •• Cottl.

CANADA ,'

,eIo-pIt ..... -"" IS WH,teclill" " ·1233

99 F'o . .. ' Po.~w .. " . To.o" lo 15, Onlo.lo r~-.r6CH.....,6-2171

'Ropoir ...... ic .. 0'0 oyo~oblo olthe.o dlol .. cI offlc ...

GENUAl IAOIO COMPANY / OVn.SEASI. ZU.ICH, SWlTZERLANO

UnUENTATlVES IN PRINCI'Al OVERSEAS COUNT.IES



A TEST OSCILLATOR FOR S-BAND MEASUREMENTS

With the Tn'];; 1360-.\ ~ 1i('rownH' o.,>

~ GENIRAl RA DI O EXPERIMENTER

4

pilot Inmp indiC'ut

freq uencies {:all be applied by fin ex· lernal BOurec. Rcconuncndf'd i'OUrf'CS arc t he '1"1'1'£ 1210-C Ll1it He Ostilbl0rand the Tn}; 1217-B Unit Pulse Generator. Tht' lal\('1' is al:

6

GENEIAl IADIO EX PER I MENtER

0.""",

Figu •• l • . S.h.moti. for .qua •• • wo". modulo _

lion.

~~r1-1---~~~ •• k , ,

'- ____ ~a.!'..!.'-':!.~~,£!,'!.~' _ _ ___ _ __ ....1

O[h ~:~::: ~ , ~ L----------.[,~·~ .. [l==::r---------l .";,~.~ ... ' .-

". O",-ar~. ..00

again, the frt'quellcy may ,.hift hy tIS Illu{'h us !l nwgaey('[e. For short pulses, the fn'quelley shift d()('s not umount to very Illueh, llnd, sin('(' the grid is the pul,.ing Illember thnt giv('i\ the bc;;t risc lime, it is used for pulse modulation. For S

The intcrn:l l lwrro\\ -ha nd sweep !It lillc-fr('(llH'llcy o r I-kc I'I~tl'S is pl'ociu ('("d by application of 1111 internally gCJl{'I": l ll'd ~:lwtooth milage to the 1l'p!'lIcf. Owillg 10 thl' inhefCnt Ch:lNif"t (" l' i:" 0.25 (.~. After W:lrlll-Ilp, frpqucrwy hI ~I"hle w.thin IIppro~iml\l('lr 5 ppm. • • ,Id .. ol FM : .'ppn.xilnoolp ly 0 .5 Ilpm in Ihe lower freqllt'n

8

GENERAl RADIO EXPERIMENTER

SPECiFICATIONS (Co nI.) GENERAl

'-""'nol.: HF 011'1)111, TY PE 871 Locking Con-lM! hot h dr,.imblc lind pmetif'a l. J n the rC'df':

JANUAR Y - FE8RUARY , 196 2

TABLE I

Comparison af Major Cha racteristics of the Types 1217-A a nd 1217· B

Ch."a"as; t-x-illg nl'itlll' r wholly "t r:lII;:istori1.ed" Hor wholly "vllclHlm tubc-iZ

10

GENERAl RA DIO EXPERIMENT ER

fr('QlIl'lH'Y from de to o\'er onc megacycle P(:I' !il"i·oncl . C'onw'ntional .VC'~, hilt C,"('I',y ll(,t i v(' P:lrt of t hi" ill))lIt-triggcrLng ci l·('uit. is eOIl\'crte(1"1\ d re',, ' ..... nfill' '''1'' ;nn i. ;,I

•

•

••

Figu •• 4. W".m.up I •• qu.n.~ d.lh of prJ d.cult 0' 10 kc .

t he input circuit jg COIl\'c rl,('C:1 to 1111 usf'iIJutor. Th is Q::;rillutor configu ra t iun is obta ined when I he swit.ches of I''ig:urc 3 fire thruwn to the "0" JXlsit ion. Note thnt the Scl unitl-ci rcuit s tl"lLChlf'C is not dis! u rhcd---cx('('pt t h:l.t the pht.c voltnge of the left-ha nd sid c is directly t.:Quplcd to th(· Icft-hund grid of V, by VI which has I)(.'

12

GENERAL RADIO EXPERIMENTER

.,,.,

" ~/.

*' DELA'YED SYNC ....

fl gu•e 5, Elemen'a.y Ichematle of the pulle_ tlmln ll ond outpul

cI,euit.,

~~ --'-

I " 'l. :J', I.:: Y

3 0, " f" I£! ~,u " r; " . ~-

, v LS =,J" ~--13~

(~" \.,::V [

"fi7I ['!::v' X

-j START

tion is &'t uy (hI' cnthodc current of the llmpliludr'-{'oJl1pluatol' :-lchmitt in R" Any \'arj:ltinIlS in this f'w'n'nt \rillllfTcct bOl h I he initi.ll and lirml \'oltagc \'alucs, Again, a s in the input ('ircnit:;, this COlllpnnltOI' j~ stahilized by hCllVY cur-l'('llt fl'('dha('k and the triggering voltage is df'termincd by precision resistors,

Output Circuits

F'igurc 5 also shows the output cir-('uit;;, Ikfol't, a st.art triggN pulse is !'!'L'(>ivet! from the input ci r('nits QJ is on :lnd Q! ofT, r ~ i:i thNdorc conductiug at. (neurly) zNo-l"ias 11nd 1'. is ofT, When [l. lrigg!'r pulSf' is rCN.,j\'cd Q~ goes on bring-ing \'4 all, 1'1 lind V. lire a pair of power pentodc,.; wilic,h pass 40 ma when on at zcrv-hiu>I, The illtcrruption of plate currcnt ill \ '3 prod UN'S a -IO-\'olt posit.ive pul~ il~ il s load 1'C.'u nd an internll l strl1y-cll ptwit:U1 CC of a pproximately 30 pf. With no external louding t he rise time of voltagt' is a p-proximutely GO lisee, 8xtenllll capaci-tance will increase this rise time by

O,I2'/J.eep~l .. ln 1-n.ee .i •• lime .ampli .. ~ .y ... m; 20 " •• c/eRl,

Pali l iv .. "an.i,ion, 10 " •• clem

Negotive !.o".ilion, 10 n .. e/em

Floute 6, O .. lIIoo.om Ihowl"l1 'yplcol ou tput I'on"lllo"" In a 50-ahm 'y"e m ,



0.4 v"ll, p"o\c_lo·p.ok, ,nlo 10 ohm.; O.ll'udem

4 vOItI, peok·lo'~DOk, Inlo 100 oh",", 0.1 I'".clem

~O yoh l, peak-Io-peak, inlO l\e;lol, ... ; O.I /o'uc/em

Fig", . 7. OpDn.el,cul! ,IID'and loll-lim. olcllla· g,am,; 'SCapI hal I::l.-pf pr"b ••

approximately 2 nsec pL With this out-put

GENERAl RADIO EXPERIMENTER

, 9:: 1 dlvio lonol I-Me I~p", .1"" wove 1 1L'.';c .. ; ptf .. I11.Hc

• 20:1 dlvlo l"" of I-Me Inp'" lin. wove

C C .... pl .. pul •• I, .... IWO ge ... ,ollll's in p

JANU A RY _fEB RUARY , 196 2

SPECIFICATIO NS (ConI.)

Hille lind fnll limlJ:!! typically 00 usee + 2 usee 'pf (''(l"rulll IOl!.d cupHcitltnce. VoU",., I'o~itivf' ,mil ncg:ltivc 4().tntL ('urrCll t 1)\lI~1!>l a\'l1iluhle ~imlllt8Iloo\lBly. DC ('(lUpled, \\'i1h de t'Olllpon('n t lIe~Fllive witll fCdP(·(:t to ground. -10 volta peak Hllo I-kilohm iutcnml load impedlHwe for hoth n~lltive nnd positive plll~f's. Output t:outrol lIIurkt:d in app!"Qximate output impo'(ianr-e.

0".""0,,1: UV(,ll!iloolti lind noi:se in puWo, lei!!! lhflfl 5 (;' of amplitude with corrt'Ct terminlltion.

ltllmp-off: Ie&! thlm I % everywhere.

Sy,,(i program channC'ls which fire identified \\"ith orlho~onfll modulations of lhe waHs of 3. single groove. The left chann("1 l'orl'cspond ... to thl' inner groo\'c wall. thl' one closest. to till"' center. and tht' ril!:ht channl'l 10 thl' olllN groove walt (u way from the cellI cr) . The po~it ivc diN.'ction.~ of 01('.'>(" modulations UI'C at

15



16

OfNEIAl IA OIO f X'fIIME NTEI

+450 and _4.')° to th(> J'{'('()rd !!;urfacc, i'f'spt'cth'('ly (Fi~ur(' I), Th{' pickup has fI !

! ,

I

JANUARY _ fEBRUAR Y, 1962

I ,

FlgII" l_ Alllom .. 'i~ony plo". d ... pon .. of Iyplcol hillh -II ... d. m"lInlll~ plck .. p . Upp .. cll ' yl I. dl.u ' ... pon • • of on , ~honn. l l lo w .. ~ .. ry ' " c.ol1'oll< f.om o'h .. cho nn.1.

then l'i),l'S COJIliUlIOtisly to 20,000 eps in 2~llog (20,000 40) = G4.8 ;;.ceolld.~. :\ext, :m iuler\"ul i:-l nllowcd for tho OIX'rtllOr to IT'l'C't Ihe remrder chnrt hnck to the 10 cps ()rdi nate. Then , thc right-{'hallncl I-ke tOI\{' is hO[l rd , being followC'd b~' the right-f'h:UlI1C'l "\\'!'Cp. If OIiC ch:mllcl of n ph-kill) IIH(ler test is cOl)llccl('(1 10 the n '('(,rucr ( lhl'OI lgh n suitnbl(, nmplifif'r), thf"l till' I'Cl'pol1sc-f,'cf]ucn(·y :ind the {'ro:'~tuJk-f r('-snilJ(' Ih(' p(, .. formnl1cc of Ih(' pi(·ku l),

I'r-I)('urn flal when 1I)(':I11 Im.~ I"£',:ollant 1X':lk~ or dip~ in bet\\"('('11 the ~pot fJ"('{llIen('ic~.

The .. pot-frequency haud" ill tIll' STH 100 rccof(1 :Ii){)\'e 50U cp .. w{'l"e ellt wilh the S l111{' I"f'cordl'r ",'(01111' !l S W(,f(' ,he sw('Cp-tUII{' lIallds. Thi ::; IlI' nnilt('d lilt nbsolute cnlibmliOl1 of the ·>

~ GENERAL .ADIO EXI'ERIMI!.NTER

18

!rie) pickup will produce a constant oul l)lIl nt nil frf'quf'llcif's, while n. vctoo-iIYM]'l:'sl>Ollf:i,'c pit'kup (Illugudic, movM ing ('oil) will produoo an output. directly pruportional to fre'lu(,lIcy. 011 the other hand. n (..'01l8Iant-w·lot'ity recording will produce 11. oon"tll1ll output with a velot· ity·rc;.polI!s if th(' gl'llertltcd VOhtlge is difTl'n'l1ti:lted by (;OI1lI('cl ioll :ICroSS tho

'. '. '. , • , "

/'

, • • a

IIIlQWICI 1ft ClCUS I'U YCQPjO

~ - =

pickup terminals of a rcsi;:.ta nce which is sInali compftl't'd to t he Cap:lCil i,'c rc-1l{'lnJll'c of the pickup. l;slIHlly a 10,000-ohm !'cs i~lor will su ffi ce. The 1X!f;.!Xm;S - constant dii

,.. i.:;tie which is obltl ined is shown in Fj~urc 4.

Whell the pil'kup i~ II Inll' ,",'Iori ly-l"C!OpolI"i\'(' devie£', it follow:! Ihal the pickup pn'umplifkr "hould h:l\'c :UI ill-\'ersc HIAA char:u·U'ti"lie. This dmr-lu·t('ristic of the prcamplifif'r is most collvcllif'ntly wrilied by the illSt'rtion of nn HIAA gClleratOI' network bct,wC'Cn thc oscillator and thc illllplificr unde r tcst. Onc !Ouch nelwork is tiho\\'11 ill Figure 4. If the m

~ G EN ER AL RADIO EXPERIMENTER

20

Flg .. t. 5, A .. lo motic co ntt ol cl te .. it lot ,h • •• co.d • • ,

."upply through ('Olllnct L At the C('.'l.'>a-tion of Ihe h·ying 1011(', HI i:< d(,-j'Hl'rp;ized Ilwrl'iJy 11cttUlIing !\ :J, \\'hil'h start!'; thl' r('uorcler motor Ilt the illl;:taill Ihe !

J ... NU ..... Y . fEB .. U ... IY, 1962 ~

in~trll('tion;;: nrc in(']uded \\it h (':\('h I"('('ord for t('sting freqlH'IH'Y rang(' of t he reprodu('ing 1:-' in mal('rial and t(-,('\lIliqu(-''-'i ha\'e made pO!l.

22

GENf R Al RAOjO [XPf R IMEN TfR

"= s pac'rd , nppro; rrom 50 Iv 10,000 "1~~: ,\(OC>< not O"t·~'t.'.1 \..;) , Ib frOlll 2Q to '20,000 "ps. . ... " . do n • • R"ng. : 0 .0 o hm to 32 kilvhm~ i n 11m r:u 'gl'.'; .\'iel, linj( -18 imliv idunl imj )(-'t.l:IncC!j ~p:)(','d ': . 4 upllrl. . mpedon.e .... curo cy: .\ [oximmn {"rrot UUCl! no t (>)(w.,j ± /jc ;, fn)m 100 \0 10,000 q )ll or ± SO y";, f ro ll> 20 to 30,000 q )!l .

Wo ve'''rm Err" r: ,,\ q\w .• i-rms IIWlo'r is uJ;(!(1 "hi(' h lI'ili indkal C lrul' r rns \\'i ~h as m uc h lUI 2flq , SN'(" ,,1 al)d third h" rmltPl;c~ .

Cobin. ' , Hlwk· h(.'lwh i Pl~ ' nmll'!\ 1 (·" h iIWl, " Iuminum pHn,.1 ( 'nhi nCI 1,11;: c" 1I',, ~ion t (')(~ 10

Ix-rmil iUO'lrunwn l to 10(' ""t'

JANOAIIY . fE6110AIIY . 1962

- THE MEASUREMENT OF THE BALLISTICS OF

INDICATING INSTRUMENTS

Tiu' hu lIist it' eh:)l'a('/rristil'!, of Ino\·ill l.!:~ ('oil ('i('('t r jl'al ilidiclililig ilISll'U1IWlltS al"(' illll>llrtalll in many :Ipplieul ioll"'. for I'xH lI1 plc , ill Vl ' n1rlcl'l', !l4:.lll1ld-l('n'l 1111·1(' .... , nlld modulation Illonito ..... TIll'Y (':111 1)(: ulliqm,ly d('fil1('d ill tcrm~ of (1 ) J,. rt.'~il; hMt -1'irl·ll it l'd.

:-itrol"lOS('opi c ligh t oIT('I"S fI m('alllS of dl'h'l'lIlillilll,!; (2), (3), nnd (4 ), wlii lc ( I) i" (,tI"lIy ll1('tll'lU1.:d by 3 1'011 \ '(, l lliolllll "rid~t, . One method o f 1ll(':t" III"('IlI('1I1 prt'\' ioll~lr dc~:ril}('(I ' u>«i a t'OlitilluOUS-film ,·anwr..! III ('onjlliletioll Ilitll H ", I mllQ ... t'II IX! ,

, \ IWI\' tt'(' llIIiquc of lYi{'tl:-

~ GEtIEIt"l RADIO EXPERIMENTER

24

c\cdric power is suddenly !Ipplicd from fl hil!;h impt.'d:UI(,(, source' j lik('\\'isc, f:tll time 3;;; "til(' tim'('d. 011(' crlcrgiZN.i whell lhl' e\t'dri('ui illSl rUlllcllt j,.. C'11C'rgi1.ed and till' other "h('ll Ihe cI('('\l' ie:l] instruIHeHt. i~ :-horl ('in'lIi lt'd. Oll{, generator is :'('t. to the slX'eifi('d ri:

the general r a d i 0 · the general r a d i 0 volume 36 nos. 1 & 2 january.february, 1962...

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